1. Field of the Invention
The present invention relates generally to selective calling radio pagers of a repeat call paging system where multiple copies of a message are transmitted in successive frames, and more specifically to a power savings technique for saving the battery power of the radio pagers.
2. Description of the Related Art
To increase the probability of signal reception by a radio pager in a wide variety of communication environments, a paging signal is transmitted in a sequence of frames each containing a series of fields which are respectively assigned to different pagers. A pager's message is copied and multiple copies of the message are transmitted in the assigned field of successive frames. Since the number of fields in a frame is limited, each field is commonly assigned to a group of pagers. As a result, a pager has to determine the identity of its assigned field on receiving a frame and if the identity of the assigned field is established and the pager's address is contained in the assigned field of that frame the pager proceeds to determine whether the assigned field of the next frame contains a message for the pager. For power savings purposes, timing circuitry is provided to turn off the battery supply to the power-consuming front end (radio frequency section) during periods in which fields assigned to other pagers are being transmitted. However, the front end is repeatedly activated on receiving an assigned field during successive frames even though a message has already been received. It is therefore desirable to still save the battery power once a message copy is received.